So, basically when the mirror broke when they were, the glass pieces fell in their hands and in there fear they didn't realise the glass was between their hands, they were holding each other's hands tightly ( you can see in second last chapter)
So, basically when the mirror broke when they were, the glass pieces fell in their hands and in there fear they didn't realise the glass was between their hands, they were holding each other's hands tightly ( y... I need this to live.
I still don't get the scar on their hands